Abstract: A method of determining a preferred wireless power transmission mode is disclosed. Each wireless laser power transmission mode defines a combination of at least two laser pulses, each of the at least two laser pulses having a different wavelength. The method comprises receiving an indication of a power received at a wireless power receiver for each of a plurality of test wireless power transmissions received at the wireless power receiver, each of the wireless power transmissions corresponding to a different wireless power transmission mode; and determining a preferred wireless power transmission mode based on the indications of power received by the wireless power receiver for at least one of the test wireless power transmissions. A corresponding computer program, non-transitory memory and satellite are also provided.